Quilt Binding Calculator: Strips, Yardage and Length
Enter your quilt dimensions, strip width, and fabric width to instantly find out how many strips to cut and how many yards of fabric to buy. Supports straight-grain and bias binding in both inches and centimeters. The show-your-work panel walks through every calculation so you can double-check before cutting.
How the quilt binding calculation works
Every quilt binding calculation starts with the perimeter: 2 x (width + length). To that base you add a joining allowance (typically 10-12 inches or 25-30 cm) to cover the angled strip joins, the overlap at the start and end, and the small triangles trimmed from mitered corners.
For straight-grain binding, divide the total binding length by your fabric width to get the number of strips, round up, then multiply by the strip width to get the fabric length. Convert to yards or meters, rounding up to the nearest 1/8 unit so you are never short at the cutting table.
For bias binding, the geometry changes: you calculate the area of binding fabric needed (total length x strip width), take the square root to get the side of the square to cut, then convert that square side to yards. Bias is wasteful on fabric but stretches slightly, which helps it curve smoothly around scalloped or round quilt edges.
Straight-grain vs bias binding: which should you choose?
Straight-grain (cross-grain) binding is the go-to for most quilts. Strips are cut perpendicular to the selvage, producing a binding with a small amount of diagonal give. It is economical with fabric, easy to cut in batches, and the slight stretch helps it hug corners neatly. Most quilt patterns that specify a binding width assume straight-grain.
Bias binding is cut at a 45-degree angle to the selvage. The true bias stretches considerably in all directions, letting it wrap around curves without puckering. If your quilt has curved edges, scalloped borders, or you are binding a round table topper, bias is the better choice. The trade-off is fabric use: bias can require 30-50% more fabric than a straight-grain equivalent because the diagonal cut leaves larger waste triangles.
For a standard rectangle or square quilt with 90-degree corners, straight-grain is nearly always the right choice. Switch to bias when your design demands it.
Fabric width and selvage allowance
Quilting cotton is usually printed 44-45 inches (112-114 cm) selvage to selvage, but the usable width after removing the tightly woven selvage edge is typically 40-42 inches (102-107 cm). Enter the usable width in the calculator, not the bolt width. If you are using a fat quarter (18 x 21 inches) or a fat eighth, measure the actual usable dimension before entering it.
Pre-washed fabric may shrink by 2-3%, so account for that when using an exact remnant. When buying new fabric off the bolt, add a small buffer: the calculator rounds up to the nearest 1/8 yard, but cutting inaccuracies and fabric shrinkage can consume that margin. Buying an extra 1/8 to 1/4 yard is cheap insurance.
Joining strips and finishing tips
Join strips with diagonal (45-degree) seams rather than straight seams. Place two strips right sides together at a right angle, draw a diagonal line across the corner, sew along the line, trim to a 1/4 in seam allowance, and press the seam open. Diagonal seams distribute bulk evenly, so the binding lies flat without lumps at the joins.
Fold the joined strip in half lengthwise, wrong sides together, and press the entire length. Sew the binding to the quilt front with your preferred seam allowance (usually 1/4 in for a 2.5 in strip). Miter the corners by folding back a 45-degree pleat before continuing to the next side. Leave a 10-12 in tail at the start and end for the final connection, joining them with another diagonal seam.
Hand-stitch the binding to the back for the most heirloom finish. Machine-stitching from the front (stitching in the ditch) is faster and nearly invisible from the top.
Common binding strip widths and finished results
| Strip width | Folded width | Finished binding width (approx.) | Best use |
|---|---|---|---|
| 2 in (5 cm) | 1 in (2.5 cm) | 1/4 in (0.6 cm) | Miniature quilts, thin edge |
| 2.25 in (5.7 cm) | 1.125 in (2.9 cm) | 3/8 in (1 cm) | Traditional standard, many patterns |
| 2.5 in (6.4 cm) | 1.25 in (3.2 cm) | 3/8-1/2 in (1-1.3 cm) | Most popular, slightly fuller finish |
| 2.75 in (7 cm) | 1.375 in (3.5 cm) | 1/2 in (1.3 cm) | Heavier batting, prominent edge |
| 3 in (7.6 cm) | 1.5 in (3.8 cm) | 5/8 in (1.6 cm) | Chunky look, thick quilts |
Double-fold binding: strip is folded in half lengthwise, then sewn with a 1/4 in (0.6 cm) seam allowance.
Frequently asked questions
How much binding fabric does a typical queen-size quilt need?
A queen-size quilt at 90 x 108 inches has a perimeter of 396 inches. Adding a 12-inch joining allowance gives 408 inches of total binding. At 2.5-inch strips and 42-inch fabric width, you need 10 strips (420 inches of fabric length), which works out to about 11.67 inches or 0.375 yards. Most quilters buy 1/2 yard to be safe.
What strip width should I use for my quilt binding?
2.5 inches is the most popular choice and works well for any quilt with standard batting thickness. Use 2.25 inches if you prefer the slimmer, more traditional look or if your pattern specifies it. Go up to 2.75 or 3 inches for quilts with very thick batting or when you want a bold, prominent border-like edge.
Why do I add extra length beyond the perimeter?
The extra 10-12 inches covers three things: the angled seam at each strip join (a small amount of fabric is lost in each 45-degree seam), the mitered fold at each corner, and the overlap needed to join the starting and ending tails. Skipping this allowance often leaves you a few inches short right at the last corner.
How do I join binding strips without a visible bump?
Sew strips together at a 45-degree angle (diagonal seam) rather than straight across. Lay two strips right sides together at a right angle, draw a diagonal line from corner to corner, stitch on the line, trim to a 1/4-inch seam allowance, and press open. This distributes the seam bulk diagonally across the binding so it lies flat instead of creating a ridge.
Can I use this calculator for a hexagon or irregular-shaped quilt?
Yes. Measure the total outer edge of your quilt with a flexible tape and enter any convenient width and length that gives the same perimeter, or simply measure the perimeter directly and note that the calculator uses 2 x (width + length). For odd shapes, measure all edges with a soft tape and add them up, then treat that sum as your perimeter and enter matching width/length values, or contact us for a custom calculation.
What is the difference between double-fold and single-fold binding?
Double-fold (also called French-fold) binding is the standard: you fold the strip in half lengthwise before attaching it, so the raw edge is enclosed inside. It creates a firm, durable edge. Single-fold binding uses one layer and requires turning the raw edge under when you sew it to the back, which is trickier to keep consistent. The strip width in this calculator assumes double-fold binding.
How do I convert inches to yards for fabric buying?
Divide the total fabric length in inches by 36 to get yards. For example, 10 strips of 2.5 inches each equals 25 inches, which is 25/36 = 0.694 yards. Always round up to the nearest 1/8 yard (0.125 increments) because fabric stores sell in those increments and rounding down leaves you short. This calculator does that rounding automatically.